The objective is to establish an integrated and easily accessible database containing factual information on the carcinogenic and physical-chemical properties and environmental fate of substances that are or might be carcinogenic. The new database, to be called Carcinogenesis Information Database of Environment Substances (CIDES), with its associated software will be suitable for online search and retrieval and as machine readable products for scientists and health officials in public, private and academic sectors. CIDES will include information from existing, available databases but will go beyond them by (1) providing innovative summary information (Carcinogenicity Ratio) giving the likelihood and the strength of the evidence that a substance is a carcinogen and (2) combining physical-chemical properties and environmental fate information with carcinogenicity and short-term test data into a single source (3) increasing the number of substances, and including radioactive compounds and physical agents (4) providing primary references and negative results of adequately conducted biological tests where such information is lacking in existing databases. In Phase I of the research plan, the feasibility of the work was established successfully by constructing a prototype database for 10 substances. Implementation of Phase II will proceed with the goal of compiling information for over 1000 substances and designing an online, user-interactive access system.